Dry-shaving apparatus

ABSTRACT

This dry-shaving apparatus has a shear plate deflected into a partial toroidal shape, its surface being cooperatively engaged with a movable cutting member and having inner and outer opposing edges. A first restraining member engages and applies a torque to the inner edge while a second member slidingly engages the outer edge of the plate and resists the torque, thereby maintaining the toroidal shape.

United States Patent Zuurveen Feb. 8, 1972 [54] DRY-SHAVING APPARATUS [72] Inventor: Frans Zuurveen, Emmasingel, Eindhoven,

[58] Field of Search ..30/43.4, 43.5, 43.6, 43.91, 30/4392, 346.51

[56] References Cited UNITED STATES PATENTS 2,134,609 10/1938 Hay ..30/43.6 X 2,575,741 11/1951 Abrams et al.. ..30/43.6 X 2,595,693 5/1952 Norwood.... ..30l43.5 2,632,948 3/1953 Konrad ..30/43.6

2,677,885 5/1954 Chaun ..30/43.6 X 2,982,021 5/1961 Miller ..30/43.6 2,992,481 7/1961 Shoemaker... .30/4 I .6 3,116,551 l/l964 Anton 30/43.6 2,291,852 8/1942 Weatherford.... ..30/43.6 2,816,358 12/1957 Vivie ..30/43.6 2,952,908 9/ 1960 Starre et al ..30/43.5 3,019,525 2/1962 Bruecker ..30/43.6 3,401,453 9/1968 Bauer ..30/43.9

FOREIGN PATENTS OR APPLICATIONS 25,696 2/1949 Switzerland 30/436 353,652 5/1961 Switzerland ...30/43.92 909,590 1/1946 France ..30/43.6 624,933 9/1961 Italy ....30/43.92

Primary ExaminerRobert C. Riordon [5 7] ABSTRACT This dry-shaving apparatus has a shear plate deflected into a partial toroidal shape, its surface being cooperatively engaged with a movable cutting member and having inner and outer opposing edges. A first restraining member engages and applies a torque to the inner edge while a second member slidingly engages the outer edge of the plate and resists the torque, thereby maintaining the toroidal shape.

7 Claims, 5 Drawing Figures PATENTED FEB 81972 3539.979

SHEET 1 OF 2 INVENTOK.

FRANS ZUURVEEN AGENT DRY-SHAVING APPARATUS This application is a continuation of my prior application Ser. No. 670,506 filed Sept. 6, 1967 and now abandoned.

The invention relates to dry-shaving apparatus and firstly to a dry-shaving apparatus as described in a prior patent application Ser. No. 665,850 filed Sept. 6, 1967; now abandoned in favor of a continuation, Ser. No. 849,553, filed July 18, 1969, of the kind including a thin elastic arcuate shear plate which is provided with hair-inlet apertures and the shaving surface of which is in the form of a surface obtained by rotation about an axis of a curved line portion not intersected by the axis of rota tion so that the shaving surface forms part of a toroidal surface, the shear plate having a circular outer edge and a circular inner edge concentrical thereto, while a movable cutting member adapted to rotate or to oscillate is operative below said shear plate, the cutting member and the shear plate being pressed against each other, and secondly to a dry-shaving apparatus of the known type including two thin elastic arcuate shear plates which are provided with hair-inlet apertures and the shaving surface of which is in the form of a surface constituted by two parallel lines which each intersect one of two curved line portions not intersecting each other, lying in one flat plane and not containing these parallel lines, so that the shaving surface forms part of the surface of the two parallel cylinders, two parallel straight outer edges and two inner edges extending parallel thereto, a movable cutting member adapted to perform a reciprocating movement being operative below said shear plates and the cutting member and the shear plates being pressed against each other.

The two types of dry-shaving apparatus are referred to hereinafter for the sake of simplicity as dry-shaving apparatus having a double cylindrical shaving head.

In the case of the toroidal shaving head, the thin elastic shear plate is stretched over a likewise toroidal cutting member adapted to rotate or to oscillate. The shear plate, which is preferably flat in the nonstreched condition, has a circular outer edge and a concentrical inner edge. With or without the use of separate resilient members, it is ensured that the cutting member and the shear plate are pressed against each other when the dry-shaving apparatus is in the mounted state. The force thus exerted on the shear plate must ultimately be transmitted again to the housing of the dry-shaving apparatus, so that the means for securing the shear plate to the housing must be able to transmit the required reaction force. This involves structural problems especially for the inner edge of a toroidal shaving head below which a rotating or oscillating cutting member is operative; for a fixed part of the housing of the dry-shaving apparatus must be located beneath the shear plate at the area of the axis of rotation, since connections on the upper side of the shear plate are naturally undesirable so that the cutting member cannot be driven by means of a shaft which is directly coupled with the cutting member and the axis of rotation of which coincides with the axis ofthe tore.

In the case of the double cylindrical shaving head a similar problem is involved in securing the two parallel inner edges to the housing if there are not provided two separate cutting members.

The invention has for an object to provide a dry-shaving apparatus of the constructions described in which a joint between the housing of the dry-shaving apparatus and the inner edge in the case of the toroidal shaving head or the inner edges in the case of the double cylindrical shaving head can be dispensed with.

According to the invention, in a dry-shaving apparatus of the kind having a toroidal shaving head, the inner edge of the shear plate is fitted in a ring or a disc which is solely connected to the shear plate.

Also according to the invention, in a dry-shaving apparatus of the kind having a double cylindrical shaving head, the two inner edges are together fitted in a strip or a rod which is solely connected to the shear plates.

In one embodiment of the invention, in a dry-shaving apparatus having a toroidal shaving head, the inner edge of the shear plate is fitted in a ring or a disc which consists wholly or in part of a synthetic material. When the shear plate is shaped into the required toroidal form in ajig with a die both having a suitable shape and the inner edge is then cast or pressed. if desired, with the use of the separate ring and/or other separate components which may consist of metal into a synthetic material, the inner edge can be fitted in a ring or a disc by a method which is simple from a technical viewpoint.

In another embodiment according to the invention of a dryshaving apparatus having a toroidal shaving head, the outer edge of the shear plate is also fitted in an outer ring. This affords the advantage that the inner ring or disc, the shear plate and the outer ring are integral and this assembly can be mounted on the dry-shaving apparatus. When the outer ring in which the outer edge is fitted is secured to the housing of the dry-shaving apparatus so that the assembly is locked against displacement in the direction of rotation of the shear cutter, the torque exerted on the shear plate due to the friction between cutting member and shear plate can be transmitted to the housing via this ring.

According to another feature of the dry-shaving apparatus having a toroidal shaving head, the outer ring in which the outer edge is fitted consists, wholly or in part, of a synthetic material. The outer edge can be fitted in an outer ring by the method which has already been described for the inner edge; preferably, the inner ring or disc and the outer ring are cast or pressed in one operation.

In an embodiment of a dryshaving apparatus having a double cylindrical shaving head, the strip or rod consists, wholly or in part, of a synthetic material. The strip or rod is provided in quite the same manner as already described for the inner ring or disc and the outer ring in the case of a toroidal shaving head.

In another embodiment of a dry-shaving apparatus'having a double cylindrical shaving head, the outer edges are also fitted in a frame. This affords the advantage that the shaving head forms a unit.

According to another feature of a dry-shaving apparatus having a double cylindrical shaving head, the frame consists, wholly or in pan, of a synthetic material.

The invention will be further described with reference to the drawings, wherein:

FIG. 1 is a perspective view ofa spring element for explaining a principal underlying this invention,

FIG. 2 is a perspective view of a double spring, similar to FIG. 1,

FIG. 3 is a partial sectional, perspective view showing a shear plate of a rotary shaving head of this invention,

FIG. 4 is a partial elevation view in section ofa new shaving head,

FIG. 5 is an exploded perspective view of the shaving head in FIG. 4.

The principle underlying the invention will be described with reference to FIGS. 1 to 3 of the drawing. FIG. 1 shows diagrammatically a strip 1 having a constant cross section and a constant width which may be made, for example, of steel and which is arranged with sliding fit at 2, while an external torque is exerted on said strip at 4. The strip is loaded by a mass of material 3 which on its lower side has a shape such that it is in contact with the strip 1 at all points. If the strip is cast or secured, so to say, at 4 into a block of material 5 having a negligible weight and if the assembly is constructed so as to be symmetrical, the situation of FIG. 2 arises in which it is important for the block 5 to be in equilibrium without the necessity of exerting external forces on it. It is not essential that the strip 1 should have a uniform thickness and width.

FIG. 3 which is obtained from FIG. 2 by rotation, shows the principle of the toroidal shaving head according to the invention.

An embodiment of a dry-shaving apparatus according to the invention having a toroidal shaving head will now be described with reference to FIGS. 4 and 5. The housing of a dry-shaving apparatus having a toroidal shaving head is denoted in FIG. 4

by 6. The motor partially shown as 6, which may be in the form of a continuously rotating motor, drives the cutting member 7 via shaft 7'. Cutting member of which is pressed in a suitable manner as by spring 7" against the shear plate 8. The inner edge of the shear plate is fitted in a disc assembly 9 which is composed of three parts, i.e., the ring 10, the disc 11 and a filler mass 12. The ring 10 and the disc 11 may be made of metal or of a synthetic material, while the filler mass 12 may consist, for example, of an epoxy resin which may be applied in the liquid state. it will be appreciated without further explanation that the inner edge of the shear plate 8 can be fitted in a simple manner with the aid ofajig in the disc 9. For this purpose, the disc 1 1 is provided with a centering aperture 13.

The outer ring assembly retaining means 14 is composed in a corresponding manner of a first ring 15, a second ring 16 and a filler mass 17. The disc 9, the outer ring 14 and the shear plate 8 together constitute the shaving head 18 which may be secured as a separate unit on the housing 6 in a suitable manner (not shown), for example, by means of a bayonet joint. At the area of the disc 9, the shaving head may advantageously be centered, for example, in the manner shown, with respect to the cutting member 7, the ring 10 cooperating with a ring l9'which is fixedly secured to the cutting member and which may be made of a material which, in cooperation with the ring 10, exhibits favorable running properties. In order to obtain a satisfactory centering, it must be ensured that the ring 10 fits with a small amount of clearance in the ring 19 and that between the ring and the housing 6 there is such a clearance space that these parts do not touch each other at any point.

FIG. 5 shows separately and in perspective view the shaving head 18 and the cutting member 7 operatively engageable with hair-receiving slits 22 of the shear plate in the shaving head. It should be noted that in case the shaving head is not secured on the dry-shaving apparatus, as in FIG. 5, so that the shear plate is not pressed against the cutting member, this shear plate assumes a slightly different form.

What is claimed is:

l. A dry shaver comprising:

a. a housing,

b. a cutting member which has cutting surfaces, and a concentric centering ring, and is rotatably mounted in the housing,

c. a shaving head formed of (i) a resilient, shear plate having circular inner and outer edges, a plurality of hair-receiving apertures, and a cutting surface, and (ii) a circular center part to which the inner edge of said plate is fixedly attached, said plate being flexed into a partial toroid shape and disposed with the toroid axis and cutting member axis coincident, the outer edge of the shear plate engaging the housing, and the centering ring rotatably engaging said center part, and

d. means for rotating said cutting member and for urging this member toward the shear plate for maintaining their respective cutting surfaces in pressure contact.

2. A dry shaver as defined in claim 1 wherein said shaving head further comprises an outer ring which is secured to the housing, with the outer edge of the shear plate secured to the outer ring.

3. A dry shaver as defined in claim 2 wherein said shaving head comprising the center part, the shear plate, and the outer ring forms a subassembly removably attachable to the housing.

4. A dry shaver as defined in claim 1 wherein said center part is a ring or disc.

5. A dry shaver as defined in claim 4 wherein at least one of said center part and outer ring components is formed of a synthetic material.

6. A dry shaver as defined in claim 4 wherein said centering ring is concentrically secured to the cutting member and has a circular part rotatably engaged to said center ring of the shavin head.

. A shaver according to claim 1 wherein said means urging the cutting member toward the shear plate, is effective in flexing the plate into said partial toroid shape. 

1. A dry shaver comprising: a. a housing, b. a cutting member which has cutting surfaces, and a concentric centering ring, and is rotatably mounted in the housing, c. a shaving head formed of (i) a resilient, shear plate having circular inner and outer edges, a plurality of hair-receiving apertures, and a cutting surface, and (ii) a circular center part to which the inner edge of said plate is fixedly attached, said plate being flexed into a partial toroid shape and disposed with the toroid axis and cutting member axis coincident, the outer edge of the shear plate engaging the housing, and the centering ring rotatably engaging said center part, and d. means for rotating said cutting member and for urging this member toward the shear plate for maintaining their respective cutting surfaces in pressure contact.
 2. A dry shaver as defined in claim 1 wherein said shaving head further comprises an outer ring which is secured to the housing, with the outer edge of the shear plate secured to the outer ring.
 3. A dry shaver as defined in claim 2 wherein said shaving head comprising the center part, the shear plate, and the outer ring forms a subassembly removably attachable to the housing.
 4. A dry shaver as defined in claim 1 wherein said center part is a ring or disc.
 5. A dry shaver as defined in claim 4 wherein at least one of said center part and outer ring components is formed of a synthetic material.
 6. A dry shaver as defined in claim 4 wherein said centering ring is concentrically secured to the cutting member and has a circular part rotatably engaged to said center ring of the shaving head.
 7. A shaver according to claim 1 wherein said means urging the cutting member toward the shear plate, is effective in flexing the plate into said partial toroid shape. 